Emergence of a stable cortical map for neuroprosthetic control.

Cortical control of neuroprosthetic devices is known to require neuronal adaptations. It remains unclear whether a stable cortical representation for prosthetic function can be stored and recalled in a manner that mimics our natural recall of motor skills. Especially in light of the mixed evidence for a stationary neuron-behavior relationship in cortical motor areas, understanding this relationship during long-term neuroprosthetic control can elucidate principles of neural plasticity as well as improve prosthetic function. Here, we paired stable recordings from ensembles of primary motor cortex neurons in macaque monkeys with a constant decoder that transforms neural activity to prosthetic movements. Proficient control was closely linked to the emergence of a surprisingly stable pattern of ensemble activity, indicating that the motor cortex can consolidate a neural representation for prosthetic control in the presence of a constant decoder. The importance of such a cortical map was evident in that small perturbations to either the size of the neural ensemble or to the decoder could reversibly disrupt function. Moreover, once a cortical map became consolidated, a second map could be learned and stored. Thus, long-term use of a neuroprosthetic device is associated with the formation of a cortical map for prosthetic function that is stable across time, readily recalled, resistant to interference, and resembles a putative memory engram

Abscission checkpoint control: stuck in the middle with Aurora B

At the end of cell division, the cytoplasmic bridge joining the daughter cells is severed through a process that involves scission of the plasma membrane. The presence of chromatin bridges ‘stuck’ in the division plane is sensed by the chromosomal passenger complex (CPC) component Aurora B kinase, triggering a checkpoint that delays abscission until the chromatin bridges have been resolved. Recent work has started to shed some light on the molecular mechanism by which the CPC controls the timing of abscission

Anotaciones sobre la evolución de la medicina interna desde William Osler a nuestros días

Discurso de inauguración del curso 2007 de la Reial Acadèmia de Medicina de la Comunitat Valencian

El distanciamiento tecnológico en la relación médico-enfermo

Gracias a la aplicación de los descubrimientos en ciencias básicas, al desarrollo de la tecnología y al fructífero progreso de las especialidades médicas, la medicina del siglo XXI ha alcanzado cotas de eficacia y de capacidad curativa realmente extraordinarias. Los médicos de 2008 somos mucho más eficientes tratando a las enfermedades y previniéndolas de lo que eran los William Osler y Gustav Von Bergman al inicio del siglo XX. Sin embargo, junto a indudables beneficios, el impulso proporcionado por estos avances a la actividad médica ha causado también cierto grado perplejidad y confusión. Es fácil constatar un desequilibrio entre lo que la sociedad actual espera de la medicina y lo que esta puede de verdad cumplir

Flies stretch their cells to avoid a chromatin trap

Before the final step of cytokinesis, termed abscission, dividing cells need to ensure that the cleavage plane is clear of chromatin. In this issue, Kotadia et al. (2012. J. Cell Biol. http://dx.doi.org/jcb.201208041) show that in Drosophila melanogaster, larval neuroblasts elongate to allow segregation of extra-long chromatids and clearance of the midzone, thereby avoiding cytokinesis failure and aneuploidy

Los dibujos wagnerianos de Egusquiza existentes en la Biblioteca Nacional de Madrid

Around 1876, Rogelio de Egusquiza (1845-1915) -a genre and portrait painter- was led by his love lor music and literature to get in touch with wagnerism and became friend of the German composer Richard Wagner. From that moment on, his life and work were transformed, and he starts his last and most personal pictorical stage, which is dominated by Wagnerian iconography. His work -strange to the dominant taste in Spain- can only be understood in the context of his close linkage to the French world and specially the parisien capital where he lived most of his life. The drawings shown in this article belong to this last stage. They are a series of studies for the etchings and the third and last group of wagnerian oil-paintings, which he gave to the Biblioteca Nacional of Madrid.Hacia 1876, la afición a la música y la literatura llevan al pintor de asuntos de género y retrato, Rogelio de Egusquiza (1845-1915), a entrar en contacto con el wagnerismo y entablar amistad con el compositor alemán Ricardo Wagner. A partir de ese instante, su vida y obra se transforman, dando lugar a una última etapa pictórica -más personal-, dominada por la iconografía wagneriana. Su obra -ajena al gusto imperante en España -sólo puede comprenderse por su estrecha vinculación al mundo francés y, muy especialmente, a la capital parisina, donde residió la mayor parte de su vida. Los dibujos presentados en el artículo, pertenecen a esta última etapa. Se trata de estudios realizados para los aguafuertes y la tercera y última serie de óleos de este tema que el autor donó a la Biblioteca Nacional de Madrid